Clutch mechanism



pri 16, 1935. R. H, zElLMAN CLUTCH MECHANISM Filed Nov. 17, 1930 INVENTOR @y ATT RNEYJ Patentedy Apr. 16, 19354 PATENT OFFICE CLUTCH MECHANISM Roy'I-Lzeilman, Elyria, Ohio, assgnor to The Thcw Shovel Company, Lorain, Ohio, a corporation of Ohio Application November 17, 193,0, Serial No. 496,215

10 Claims.

` My invention relates to a clutch mechanism. It relates, particularly, to a clutch mechanism ofthe type embodying what is termed as a booster druml and brake band for moving the clutch parts into operative engagement, the clutch embodying the usual drum and clutch band that may be either of the expanding or contracting type.

H eretofore, there has been considerable diniculty with clutches of the drum and band type in arranging the parts and the operating speed so that the so-called chattering would be done raway with. Such chattering is usually due to a grabbing and rcleaseraction between the` band and the drum caused by vibration or oscillation lof the'operating parts and, therefore, the clutch band, and results in undue wear andstrain on all the operating parts.

My invention contemplates the provision of a means for eliminating thefchattering. action, this means taking the form of a snubber or retarderof the friction cushion and spring type, such snubber or retarder being adapted tol cause a relatively slow `and a steady movement of the friction band into or out of engagement with, theclutch drum and without oscillation or vibration i of theband.

vVarious objects and .advantageousA features may be seen in the following description and one embodiment thereof may be seeniin the accompanying drawing wherein similar characters, of reference designate corresponding parts, and wherein: f g f Fig. lis asectional View showingv a clutch mechanism that may be constructed in accordance with my invention in combinationrwith a shaft that forms: a part ofV a swing mechanism; Fig. 2 lis an elevation of aclutch band and operating partsv constructed in yaccordance with my invention; Fig. 3 is a sectional elevation ofthe friction cushion orsnubber device; and Fig. 4 isl a sectional view taken on the line 4 4 of Fig. 3. Referring tothe ,drawing, Ii have. shown, in

.Fig.1, apart of the operating mechanism usually found in power shovels or the like,A including a f liorizontalswing shaft l mounted in fixed bearings 2 and carrying a bevel gear 3 loosely mounted thereon `and'cooperating with a bevel gear .4 that isrigidly mounted on a vertical swing shaft 5. Under'certainconditions, that is, when` the horizontal swingv shaft I'which is continuously rotated through a driving gear 6 is clutched to the "bevel gearx3 through the medium vof a clutch fdrumi also loosely..mounted on the shaft and 'rigidly attached tothe bevel 'gear l3 and a clutch band; B operated Vvina manner hereinafter de- (ol. 19a-36) scribed, the vertical swing shaft 5 which is ordi- .narily stationary will be rotated to operate a turn table, swinging frame, or the like.

As shown in Fig. 2, the clutch band 8 ismounted on a frame including a spider 9, they clutch band being attached as at It) to one of the spider Aarms and guided through the remainder of its length by adjustableguide plates Il disposed at various points around `the inner circumference of the band.A A spider 9 is rigidly mounted on the horizontal swing shaft i andthe free end of the band 8 is connected tothe spider by meansof a toggle link l2 pivotally connected as at i3 to the lfree end of theband and pivotally connected as at i4 to the spider. .f i

The free end of the clutch band 8 is also connected to one end i5 of a bell crank I6 fulcrumed on the spider 9 as at Il by means of two vadjusting eye-bolts I8 having right and left hand' threads vrespectively and connected together by a nut I9 2O whereby the throw of the bell crankrelative to the bandmay be adjusted. At its opposite end, the vbell crank I6 is connected; to a pin 20 of a booster drum mechanism, hereinafter described, by means of a link 2l. With this construction, a downward pull on the link 2l will cause -down ward movement of the long end of the bell crank I5 andk movement of the short end l5 thereof kto the left as shown in Fig.2 which will increase the circumference of the vband 8 as will be readily o apparent or, in other words, will expand the band until theouter fabric or composition coating that normally forms a. part of every clutch band is moved into engagement with the inner periphery of the drum lv whereby theV drum and bevel gear 35 v3v willbe rotated at the same rate of speed as the horizontal swing shaft I since the clutch band 'is rigidlymounted on the horizontal swing shaft. Thus, the vertical swing shaft 5 will be rotated to cause movement of thev swinging frame or other parts which it drives. A release means consistingof a rod 22 extending loosely through anextension `23 on the spider 9 and through an angle 24 on .theinner periphery. of the clutch band 8 land having a spring. 25 interposed between the 4,

eXtensionZS vand adjusting nuts 26 on the lower end of the rod is pro-vided to cause contraction oftthe band 8 when the downward pull of the' link r2l is relieved, the spring 25 being compressed as the band;8 is expanded in the manner just 570 described. Y

The means for operating the clutch band or causing a downward pull on the link 2| consists of a-drumV `:2l mounted on the hub of the spider 9 which isrigidly mounted on the shaft l in 55l such manner that the drum will normally rotate with the spider 9 due to friction and its connection with the link 2l without exerting suicient pull on the link 2l to cause expansion of the band 8 but may be held against rotation with the spider 9 and shaft l to cause a downward pull on the link 2l due to retarding of the rotation of the drum 2l. An ordinary brake band 28 is provided around the drum 2'! and a suitable operating means (not shown) is provided for contracting the band 2S to grip the drum 2l in such manner as to retard its rotation but still permit slipping of the drum when the pull thereon is suicient to overcome the friction between the drum and brake band. y

In accordance with my invention, a means is provided for causing a steady movement of the band 8 into and out of engagement with the inner periphery of the drum whereby any grab and release action due, in most instances, to vibration of operating parts will be eliminated and chattering prevented, This means consists of what may be termed a snubber embodying a rod 29v pivotally connected to the outermost end of theA long arm of the bell crank I6 as at 30 and extending loosely downwardly through a sleeve 33 in the spider 9 and surrounded by a spring 3|` that is interposed between a collar 32 on the rod and the sleeve 33 in the spider. Thus, downward movement of the bell crank l 6 is resisted by compression of the spring 3l and on release of the downward pull on the bell crank it is moved upwardly by the tendency of the spring to return to its normal position. In addition to the resistance afforded by the spring 3 I a smaller spring 34 surrounds a reduced portion 35 of the rod 29 with its one end bearing against the shoulder 36 formed by the reduction in the rod. The opposite end of this spring 34 bears against the upper end of a plurality of tapered collets 31 that are disposed in an annular tapered seat formed in the sleeve 33. Thus, when the .rod 29 is moved downwardly by downward movement of the bell crank I which expands the band 8 into engagement with the drum 1, the tapered collets 31 will be forced downwardly into the tapered seat in the sleeve 33 and, since the inner surface of the collets bear against the outer periphery of the shaft 29, a wedging action will be produced which will retard downward movement of the rod 29 or upward movement of the rod after it has been moved to the lowermost extent desired, the upward movement being resisted by the drag of the collets wedged against the shaft and held by the downward force exerted by the still compressed spring 34. Thus, the movement of the bell crank I G in either direction is substantially retarded or resisted which will produce a relatively steady movement of the bell crank and prevent a grab and release action of the band 8with relation to the drum 'l which produces chattering.

With this construction, I have provided a clutch that has the advantage of being more positive in action than the usual clutch of the drum and band type due to the fact that vibration or oscillation of the clutch band will be eliminated regardless of the presence of amount of oscillation or vibration of the operating parts for the band. Together with this, the band will move into and out of engagement with the drum with a slow and steady movement due to the friction retarding action increasing in effectiveness as the band approaches drum engaging position whereby intermittent grab and release action during the time the band is being moved into operative engagement with the drum will be further done away with. This is accomplished by the snubber or friction cushion shown and described. It will be understood that such snubber or friction cushion may be as readily applied to a clutch band of the contracting type as to the expanding type shown.

What I claim is:

1.V Apparatus of the' class described comprising a clutch drum, a clutch band adapted to be moved into engagement with said drum, means for moving said band into drum-engaging position, and a retarding means including a friction cushion eiective on said band-moving means to `increasingly retard the movement of said band toward drum-engaging position as said band approaches said drum.

2. Apparatus of the class described comprising a clutch drum, a clutch band adapted to be moved into engagement with said drum, means f moved into engagement lwith said drum, means for moving said band into drum-engaging position, means including a rod operatively connected with said bandffor retarding movement of said band into drum-engaging position, a friction cushion for said rod and resilient means for resisting movement of lsaid rod toward engaged position and urging said rod toward disengaged position.

4. Apparatus of the class described comprising a clutch drum, a clutch band adapted to be moved into engagement with said drum, means for moving said band into drum-engaging position, means including a rod operatively connected with said band and a sleeve member about said rod for retarding movementof said band into drum-engaging position, means moved into wedging position between said rod and said sleeve member by movement of said band and rod toward engaged position, and resilient means for resisting movement of said rod toward engaged position. Y

5. Apparatus of the class described comprising a clutch drum, a clutch band adapted to vbe moved into engagement with said drum, means for moving said band into drum-engaging position, means including a rod operatively connected with said band and a sleeve member about said rod for retarding movement of said band into drum-engaging position, a plurality of tapered collets movable into Wedging position between said rod and said sleeve member by movement of said rod and band toward engaged position,

.and resilient means for resisting movement of said rod toward engaged position.

6. Apparatus of the class described comprising a clutch drum, a clutch band adapted to be moved into engagement with said drum, bandmoving means including a drum rotatable with said band, interconnecting mechanism between said last named drum and said band for moving said band into drum-engaging position when rotation of said last named drum is retarded, means for retarding rotation of said last named drum, aretarding means including Va friction cushion effective on said band-moving means to increasingly retard the movement of said band toward drum-engaging position, and means for moving v said band out of engagement with said drum.

7. Apparatus of the class described comprising a clutch drum, a clutch band adaptedto be moved into engagement with said drum, band-moving `means including a drum rotatable with said band, interconnecting mechanism between said last named drum and said band for moving said band into drum-engaging position when the rotation of said last named drum is retarded, means for retarding the rotation of said rotatable drum, means for retarding movement of said band intoI engagement with said drum including a rod operatively connected to said band and a friction cushion rendered increasingly eiective on said rod by movement ofsaid band toward drumengaging position, and means for moving said band out o-f drum-engaging position.

8. Apparatus of the class described comprising a clutch drum, a clutch band adapted to be moved into engagement with said drum, bandmoving means including a drum rotatable with said band, interconnecting mechanism between said last named drum and said band for moving said band into drum-engaging position when the rotation of said last named drum is retarded, means for retarding the` rotation of said last named drum, means for ret'arding movement of tion, means for retarding movement of said band into drum-engaging position and urging said band toward release position, and means for retarding the action of said last named band-moving means.

10. Apparatus of the class described, comprising a clutch'drum, a clutch band adapted to be moved into engagement with said drum, means for moving said band into drum-engaging position, means for retarding movement of said band into drum-engaging position and urging said band toward release position, and means operable by said band urging means for retarding the action thereof upon said band.

ROY H. ZEILMAN. 

